A robust and emission-compliant overpumping solution that met the specific demands of a confined space was required during infrastructure work at a pumping station in Hampshire.

Cappagh Browne, an operational partner for Southern Water, faced a significant challenge when relining work was being carried out on the underground pipework at a surface water pumping station in Lower William Street, Southampton. In addition to coping with the flows from the pumping station, the project required a solution that met the demands of a busy urban environment and a small indoor space within which to set up equipment.

Pump rental specialists at Selwood, which has its headquarters nearby at Chandler’s Ford, were contacted and carried out a full on-site assessment of the site, taking into consideration all the specific constraints of the application. After discussions with the client, the NZ Hybrid Electric pump was chosen as the best unit for the job given the tight access into the wet well.

Selwood experts carried out a full installation of the two pumps, which achieved a combined flow of 420 litres per second. Specialists set up variable drives to adjust the speed of the pumps to match the required flow. Diesel-driven pumps were not suitable for the application and an emission-compliant electric solution was required. The pump set-up utilised the 160Amp power supply, maximising flow efficiency by setting a power limit for each unit and, in doing so, removing any need for additional generators.

The demands of the site required the two pumps to exit through a rear door of the building via two 300mm steel flanged pipes. They then joined a 500mm manifold which ran 370m through a live business premises before connecting back into the underground pipework via a flowthrough stopper.

Selwood’s technical specialists set up the pumps with Milltronics devices to dynamically adapt to varying flows, while remote monitoring pump telemetry provided the on-site team with valuable information on pump performance.

Selwood and Cappagh Browne, both priding themselves on an unrivalled health and safety record, worked in unison to complete the job efficiently and seamlessly. The proximity of Selwood’s local branch and the ready availability of pump specialists, together with a 24/7 emergency call-out system, gave the client peace of mind as the job was carried out to completion.

Dallas Churcher, Project Manager for Selwood, said: “Selwood has a long-standing relationship with Southern Water and its partners and we were pleased to be able to provide a reliable and robust solution for this overpumping application.

“The restricted indoor space was a particular challenge for this project and we worked in tandem with the client to overcome any difficulties. We had very good feedback from Cappagh Browne and look forward to working with them again in future.”